Modular Air Cooled Condenser Apparatus and Method

ABSTRACT

The present invention relates to a mechanical draft cooling tower that employs air cooled condenser modules. The aforementioned cooling tower operates by mechanical draft and achieves the exchange of heat between two fluids such as atmospheric air, ordinarily, and another fluid which is usually steam. The aforementioned cooling tower utilizes a modular air cooled condenser concept wherein the air cooled condensers utilize heat exchange deltas that use tube bundles that are manufactured and assembled prior to being shipped to the tower site.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 61/828,076, filed on May 28, 2013, titled “MODULAR AIR COOLEDCONDENSER APPARATUS AND METHOD,” the disclosure of which is incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a mechanical draft cooling tower thatutilizes air cooled condenser modules. The aforementioned cooling toweroperates by mechanical draft and achieves the exchange of heat betweentwo fluids such as atmospheric air, ordinarily, and another fluid whichis usually steam or some sort of industrial process fluid. Theaforementioned cooling tower operates by mechanical draft which utilizesan air current generator such as a fan or the like.

BACKGROUND OF THE INVENTION

Cooling towers are heat exchangers of a type widely used to emanate lowgrade heat to the atmosphere and are typically utilized in electricitygeneration, air conditioning installations and the like. In a mechanicaldraft cooling tower for the aforementioned applications, airflow isinduced or forced via an air flow generator such as a driven impeller,driven fan or the like. Cooling towers may be wet or dry. Dry coolingtowers can be either “direct dry,” in which steam is directly condensedby air passing over a heat exchange medium containing the steam or an“indirect dry” type cooling towers, in which the steam first passesthrough a surface condenser cooled by a fluid and this warmed fluid issent to a cooling tower heat exchanger where the fluid remains isolatedfrom the air, similar to an automobile radiator. Dry cooling has theadvantage of no evaporative water losses. Both types of dry coolingtowers dissipate heat by conduction and convection and both types arepresently in use. Wet cooling towers provide direct air contact to afluid being cooled. Wet cooling towers benefit from the latent heat ofvaporization which provides for very efficient heat transfer but at theexpense of evaporating a small percentage of the circulating fluid.

To accomplish the required direct dry cooling the condenser typicallyrequires a large surface area to dissipate the thermal energy in the gasor steam and oftentimes may present several challenges to the designengineer. It sometimes can be difficult to efficiently and effectivelydirect the steam to all the inner surface areas of the condenser becauseof non-uniformity in the delivery of the steam due to system ductingpressure losses and velocity distribution. Therefore, uniform steamdistribution is desirable in air cooled condensers and is critical foroptimum performance. Another challenge or drawback is, while it isdesirable to provide a large surface area, steam side pressure drop maybe generated thus increasing turbine back pressure and consequentlyreducing efficiency of the power plant. Therefore it is desirous to havea condenser with a strategic layout of ducting and condenser surfacesthat allows for an even distribution of steam throughout the condenserthat reduces back pressure, while permitting a maximum of coolingairflow throughout and across the condenser surfaces.

Another drawback to the current air cooled condenser towers is that theyare typically very labor intensive in their assembly at the job site.The assembly of such towers oftentimes requires a dedicated labor force,investing a large amount of hours. Accordingly, such assembly is laborintensive requiring a large amount of time and therefore can be costly.Accordingly, it is desirable and more efficient to assemble as much ofthe tower structure at the manufacturing plant or facility, prior toshipping it to the installation site.

It is well known in the art that improving cooling tower performance(i.e. the ability to extract an increased quantity of waste heat in agiven surface) can lead to improved overall efficiency of a steamplant's conversion of heat to electric power and/or to increases inpower output in particular conditions. Moreover, cost-effective methodsof manufacture and assembly also improve the overall efficiency ofcooling towers in terms of cost-effectiveness of manufacture andoperation. Accordingly, it is desirable for cooling tower that areefficient in both in the heat exchange properties and assembly. Thepresent invention addresses this desire.

Therefore it would desirous to have an economical, mechanical draft,modular cooling tower that is efficient not only in its heat exchangeproperties but also in its time required for assembly and cost for doingthe same.

SUMMARY OF THE INVENTION

Embodiments of the present invention advantageously provides for afluid, usually steam and method for a modular mechanical draft coolingtower for condensing said steam.

An embodiment of the invention includes a method for assembling amodular air cooled condenser extending along a vertical axis away fromhorizontal, comprising the steps of: assembling a first condenser bundleassembly having a first set of tubes having first and second ends, asteam manifold connected to the first ends of the tubes, and acondensate header connected to the second ends of the tubes; assemblinga second condenser bundle having a second set of tubes having first andsecond ends, a steam manifold connected to the first ends of the tubes,and a condensate header connected to the second ends of the tubes;placing the first and second condenser bundle assemblies in to acontainer; transporting the container to a location upon which themodular air cooled condenser will be assembled; assembling a heatexchange delta by placing the first condenser bundle and the secondcondenser bundle; and positioning the heat exchange delta on a modulartower frame.

Another embodiment of the present invention includes a modular aircooled condenser extending along a vertical axis away from horizontal,comprising: means for assembling a first condenser bundle assemblyhaving a first set of tubes having first and second ends, a steammanifold connected to the first ends of the tubes, and a condensateheader connected to the second ends of the tubes; means for assembling asecond condenser bundle assembly having a second set of tubes havingfirst and second ends, a steam manifold connected to the first end ofthe tubes, and a condensate header connected to the second ends of thetubes; means for placing the first and second condenser bundleassemblies in to a container; means for transporting the container to alocation upon which the modular air cooled condenser will be assembled;means for assembling a heat exchange delta by placing using the firstcondenser bundle and the second condenser bundle; and means forpositioning the heat exchange delta on a modular tower frame.

Another embodiment of the present invention, A mechanical draft modularair cooled condenser that cools an industrial fluid is disclosed,comprising: a plenum with which at least one delta resides wherein saidat least one delta comprises first condenser bundle having a first setof tubes having first and second ends, a steam manifold connected to thefirst ends of the tubes, and a condensate header connected to the secondends of the tubes; and a second condenser bundle having a second set oftubes having first and second ends, a steam manifold connected to thefirst ends of the tubes, and a condensate header connected to the secondends of the tubes; a support frame that supports said plenum; and ashroud that houses an air current generator.

In yet another embodiment of the present invention, a method forassembling a modular air cooled condenser extending along a verticalaxis is disclosed, comprising: assembling a first condenser bundlehaving a first set of tubes having first and second ends and acondensate header connected to the second end of the tubes; assembling asecond condenser bundle having a second set of tubes having first andsecond ends, and a condensate header connected to the second end of thetubes; placing the first and second condenser bundles in to a container;transporting the container to a location upon which the modular aircooled condenser will be assembled; assembling a heat exchange delta byplacing using the first condenser bundle and the second condenserbundle; and positioning the heat exchange delta on a modular towerframe.

There has thus been outlined, rather broadly, certain embodiments of theinvention in order that the detailed description thereof herein may bebetter understood, and in order that the present contribution to the artmay be better appreciated. There are, of course, additional embodimentsof the invention that will be described below and which will form thesubject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of embodiments inaddition to those described and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein, as well as the abstract, are for thepurpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be utilized as a basisfor the designing of other structures, methods and systems for carryingout the several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of thisdisclosure, and the manner of attaining them, will become more apparentand the disclosure itself will be better understood by reference to thefollowing description of various embodiments of the disclosure taken inconjunction with the accompanying figures.

FIG. 1 is a top view of a power plant with heat exchanger having an aircooled condenser module in accordance with an embodiment of the presentinvention.

FIG. 2 is an elevation view of the air cooled condenser module depictedin FIG. 1 in accordance with an embodiment of the present invention.

FIG. 3 is a sectional view of the air cooled condenser module depictedin FIG. 1 in accordance with an embodiment of the present invention.

FIG. 4 is a perspective view of the air cooled condenser module depictedin FIG. 1 in accordance with an embodiment of the present invention.

FIG. 5 is a perspective view of a braced bay for the air cooledcondenser module depicted in FIG. 1 in accordance with an embodiment ofthe present invention.

FIG. 6 is a perspective view of a duct, risers, and middle truss for theair cooled condenser module depicted in FIG. 1 in accordance with anembodiment of the present invention.

FIG. 7 is a perspective view of an assembled duct, risers, and middletruss for the air cooled condenser module depicted in FIG. 1 inaccordance with an embodiment of the present invention.

FIG. 8 is a perspective view of the assembled duct, risers, and middletruss disposed on the braced bay for the air cooled condenser moduledepicted in FIG. 1 in accordance with an embodiment of the presentinvention.

FIG. 9 is a perspective view of transversal structures on the assembledduct, risers, and middle truss disposed on the braced bay for the aircooled condenser module depicted in FIG. 1 in accordance with anembodiment of the present invention.

FIG. 10 is a perspective view of a transversal truss for the air cooledcondenser module depicted in FIG. 1 in accordance with an embodiment ofthe present invention.

FIG. 11 is a perspective view of the transversal truss and transversalstructures on the assembled duct, risers, and middle truss disposed onthe braced bay for the air cooled condenser module depicted in FIG. 1 inaccordance with an embodiment of the present invention.

FIG. 12 is a perspective view of a longitudinal truss for the air cooledcondenser module depicted in FIG. 1 in accordance with an embodiment ofthe present invention.

FIG. 13 is a perspective view of the longitudinal truss, transversaltruss, and transversal structures on the assembled duct, risers, andmiddle truss disposed on the braced bay for the air cooled condensermodule depicted in FIG. 1 in accordance with an embodiment of thepresent invention.

FIG. 14 is a perspective view of a bridge for the air cooled condensermodule depicted in FIG. 1 in accordance with an embodiment of thepresent invention.

FIG. 15 is a perspective view of the bridges, longitudinal trusses,transversal trusses, and transversal structures on the assembled duct,risers, and middle truss disposed on the braced bay for the air cooledcondenser module depicted in FIG. 1 in accordance with an embodiment ofthe present invention.

FIG. 16 is a perspective view of a partial placement of headers anddeltas for the air cooled condenser module depicted in FIG. 1 inaccordance with an embodiment of the present invention.

FIG. 17 is a perspective view of an air cooled condenser module inaccordance with an embodiment of the present invention.

FIG. 18 is a schematic side view of the air cooled condenser moduledepicted in FIG. 1 in accordance with an embodiment of the presentinvention.

FIG. 19 is another schematic side view of the air cooled condensermodule depicted in FIG. 1 in accordance with an embodiment of thepresent invention.

FIG. 20 is a perspective view of an A-type condenser configuration inaccordance with an embodiment of the present invention.

FIG. 21 illustrates the condenser bundles in a packaged arrangement forshipping in accordance with an embodiment of the present invention.

FIG. 22 schematically illustrates the steps of assembly of an air cooledcondenser in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof and show by way ofillustration specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice them, and it is to beunderstood that other embodiments may be utilized, and that structural,logical, processing, and electrical changes may be made. It should beappreciated that any list of materials or arrangements of elements isfor example purposes only and is by no means intended to be exhaustive.The progression of processing steps described is an example; however,the sequence of steps is not limited to that set forth herein and may bechanged as is known in the art, with the exception of steps necessarilyoccurring in a certain order.

Embodiments described herein provide a heat exchange system, a supportstructure for an air cooled condenser (“ACC”), and a method ofconstructing a support structure for an ACC. As described herein, someor all of these embodiments provide substantial benefit over standardA-frame ACC. Examples of benefits over standard A-frame ACC includereduced cost of about 25%, improved constructability, higher annualoutput of power plant, improved cleanability due to use of motorizedcleaning shuttlestandard, lower visual impact due to reduced height (26m vs. 32.6 m) and reduced occupied ground area, and reduced foundations(40 columns vs 48 for A-frame ACC with equivalent output). This heightreduction is due to the reduced height of the multi-deltas describedherein compared to conventional A-Frame-type bundles that have longertubes and increased overall height.

Specific examples of reduced cost and improved constructability include:Steam manifolds and steam condensate headers already welded on finnedtube bundles in the manufacturing factory; Less total weight of steelstructure (−25% vs A-Frame ACC); Less total weight of ducting (−25% vsA-Frame ACC); Reduced number of bundles (25% for A-Frame ACC); Fewerelements of steel structure to be assembled on site by bolting (−50% vsA-Frame ACC); Reduced site welding length on ducting (−50% vs A-frameACC); Fewer lifting operations; Shorter construction duration; Fewer manactivities at height due to more preassembly which results in improvedoverall safety level; Less scaffolding required; Higher proportion ofpiping and piping supports preassembled in the manufacturing factory onthe finned tube bundles; Important proportion of assembly on site is atground level (bolting of delta, liaison duct, . . . ); No cleaningladder required; and More containerized deliveries.

Specific examples of higher annual output of power plant include: Lowerback-pressure during low ambient temperature periods (e.g., below 9° C.)which results in higher power plant output during low temperatureperiods; and lower minimum back-pressure (62 mbar vs 70 mbar for A-FrameACC) which results in higher power plant electricity production on ayearly basis (+0.4% vs A-Frame ACC). More particularly, theback-pressure may be reduced because the heat exchange tubes in thebundles (described herein) may be made shorter and more numerous incomparison to an A-Frame ACC. In this manner, the total surface area maybe equivalent while the velocity in the tubes is reduced. It is yetanother advantage that the reduced velocity results in a correspondingreduction in erosion of the tubing.

FIG. 1 is a top view of a heat exchange system 10 having an air cooledcondenser module 12 in accordance with an embodiment of the presentinvention that is suitable for use with a heat generating facility suchas a power plant 14. As shown in FIG. 1, the heat exchange system 10includes an understructure 20 to support the other elements of the heatexchange system 10 such as a supply line 22, risers 24, headers 26, topmanifold 28, coils or bundles 30, fan 32 and bell housing 34. Inaddition, a return line 36 is configured to return condensate to thepower plant 14.

In use, the power plant 14 generates heat to create steam to driveturbines to generate power in a manner generally known to those skilledin the art. After steam has passed through the turbines, the steam stillretains substantial waste heat which is removed by the heat exchangesystem 10 and the condensate is returned via the return line 36.

FIG. 2 is an elevation view of the air cooled condenser module 12depicted in FIG. 1 in accordance with an embodiment of the presentinvention. As shown in FIG. 2, the understructure 20 occupies arelatively small area which results in great open space below the aircooled condenser module 12.

FIG. 3 is a sectional view of the air cooled condenser module 12depicted in FIG. 1 in accordance with an embodiment of the presentinvention. As shown in FIG. 3, the supply line 22 is depicted reducingin size as it proceeds along the air cooled condenser module 12. Ingeneral, as the risers 24 channel steam from the supply line 22 to thetop manifold 28 and bundles 30, the size of the supply line 22 isreduced accordingly.

FIG. 4 is a perspective view of the air cooled condenser module 12depicted in FIG. 1 in accordance with an embodiment of the presentinvention. As shown in FIG. 4, the headers 26, top manifold 28 andbundles 30 as well as the fan 32 and bell housing have been removed forclarity to show the understructure 20. In the following FIGS. 5-16 aninventive sequence of construction for the air cooled condenser module12 is illustrated in accordance to an embodiment.

At FIG. 5, a braced bay 50 is disposed a construction site for the aircooled condenser module 12 depicted in FIG. 1. The braced bay 50 isconfigured to support one of the air cooled condenser modules 12 on fourfeet 52. In typical construction, a foundation is disposed in the groundbelow each of the feet 52.

FIG. 6 is a perspective view of a duct 60, the risers 24, and a middletruss 62 for the air cooled condenser module 12 depicted in FIG. 1 inaccordance with an embodiment of the present invention. As shown in FIG.6, the risers 24 and duct 60 may be pre-assembled at a manufacturingfacility and container shipped to the building site. Similarly, themiddle truss 62 may be pre-assembled at a manufacturing facility andcontainer shipped to the building site. This and other pre-assemblydescribed herein facilitates a reduction in labor costs and improvementin quality of construction. For example, at the production facility,welders may be protected from rain and other elements that may otherwisereduce weld quality. However, in other embodiments, the risers 24 may beaffixed to the duct 60 after placement on the understructure 20.

FIG. 7 is a perspective view of an assembled duct 60, risers 24, andmiddle truss 62 for the air cooled condenser module 12 depicted in FIG.1 in accordance with an embodiment of the present invention. In anembodiment, the assembly may be performed on the ground at the buildingsite or at the manufacturing facility. At FIG. 8, the assembled duct 60,risers 24, and middle truss 62 is shown disposed on the braced bay 50for the air cooled condenser module 12 depicted in FIG. 1. For example,the assembled duct 60, risers 24, and middle truss 62 may be lifted by acrane and disposed on the braced bay 50.

At FIG. 9, a plurality of transversal structures 90 are disposed on theassembled duct 60, risers 24, and middle truss 62 disposed on the bracedbay 50 for the air cooled condenser module 12 depicted in FIG. 1. Forexample, the transversal structures 90 may be welded or bolted to thebraced bay 50 after being lifted by the crane.

FIG. 10 is a perspective view of a transversal truss 100 for the aircooled condenser module 12 depicted in FIG. 1 in accordance with anembodiment of the present invention. The transversal truss 100 may bepre-assembled at a manufacturing facility and container shipped to thebuilding site. At FIG. 11, the transversal truss 100 is shown attachedto the transversal structures 90 on the assembled duct 60, risers 24,and middle truss 62 disposed on the braced bay 50 for the air cooledcondenser module 12 depicted in FIG. 1. For example, the transversaltruss 100 may be welded or bolted to the transversal structures 90 afterbeing lifted by the crane.

FIG. 12 is a perspective view of a longitudinal truss 120 for the aircooled condenser module 12 depicted in FIG. 1 in accordance with anembodiment of the present invention. The longitudinal truss 120 may bepre-assembled at a manufacturing facility and container shipped to thebuilding site. At FIG. 13, the longitudinal truss 120 is shown attachedto the transversal truss 100. For example, the longitudinal truss 120may be welded or bolted to the transversal truss 100 after being liftedby the crane.

FIG. 14 is a perspective view of a bridge 140 for the air cooledcondenser module 12 depicted in FIG. 1 in accordance with an embodimentof the present invention. At FIG. 15, the bridges 140 are connected tothe transversal trusses 100 on the braced bay 50. For example, thebridges 140 may be welded or bolted to the transversal truss 100 afterbeing lifted by the crane.

FIG. 16 is a perspective view of a partial placement of the headers 26disposed on the risers 24. The headers 26 are shown connected to the topmanifolds 28 which supply steam to the bundles 30. A delta 160 is anassembled set of top manifolds 28 and bundles 30.

Turning now to FIG. 17, the modular air cooled condenser module 12 isillustrated on a simplified understructure. The air cooled condensermodule 12 generally includes a plenum 170, having an air currentgenerator or fan disposed within a fan shroud or inlet bell 34 and theunderstructure 20 is shown in a simplified form for the sake of clarity.The air cooled condenser module 12 further includes multiple A-typegeometry deltas, each designated 160. Each delta 160 comprises two tubebundle assemblies 30 with a series of finned tubes to conduct heattransfer. The deltas 160 will be discussed in further detail below.

Turning now to FIGS. 18 and 19, schematic side views of the air cooledcondenser module 12 are depicted. As specifically illustrated in FIG.18, the air cooled condenser employs risers 24 which are welded to themain steam duct 22. The risers 24 are connected to a steam manifold 28which operates to keep the steam flow velocity more constant. This abovedescribed configuration is part the A-type condenser bundles 30 that areshipped as a unit from the factory, which will be discussed in furtherdetail below. The condenser bundles 30 are preferably welded to therisers 24 via a transition piece 26 to accommodate the geometry of thesteam manifold.

Turning now to FIG. 20, a delta 160 is illustrated. As depicted, eachdelta 160 is comprised of two individual heat exchange bundle assemblies30, each having a series of finned tubes. The individual tubes areapproximately two (2) meters in length whereas the bundle length isapproximately twelve (12) meters. As illustrated, each bundle assembly30 is positioned at an angle to one another to form the A-typeconfiguration of the delta 160. While the bundle assemblies 30 may bepositioned at any desired angle, they preferably are positioned at anangle approximately twenty degrees (20°) to approximately thirty degrees(30°) from vertical and approximately sixty degrees (60°) toapproximately seventy degrees (70°) from horizontal. More specifically,the bundle assemblies 30 are positioned at twenty-six degrees) (26° fromvertical and sixty-four degrees (64°) from horizontal.

Each of the bundle assemblies 30 are assembled prior to shipping whereineach comprises a riser to header transition piece 202, steam manifold204, finned tubes 206, and steam condensate headers 200. As can be seenin FIG. 17, due to the modular design and orientation of the bundleassemblies 30, the air cooled condenser design 10 has approximately five(5) times more tubes as compared to typical designs. Moreover, theembodiments of the current invention not only utilize five (5) times thetubes, but employ condenser tubes that are much shorter in length. Asresult of the aforementioned design and orientation, the steam velocitytraveling through the tube bundles 30 is reduced as result of theincreased number of tubes in combination with the reduced tube length,and therefore steam pressure drop within the deltas 160 is reduced,making the air cool condenser 10 more efficient.

Typically, turbine back pressure of an air cooled condenser or the likeis limited by the maximum steam velocity in the tubes (to limit erosion)wherein the steam velocity is increasing with a decrease of backpressure (due to density of steam). Thus, due to the addition of tubesin accordance with the present invention, the steam is still maintainedat the maximum allowable steam velocity but at a lower back pressure.The other limitation the current delta design addresses is that thepressure at the exit of the secondary bundles cannot be less than thevacuum group capability. This pressure typically results from turbineback pressure minus the pressure drop in ducting minus the pressure dropin the tubes. Accordingly, due to the reduced pressure drop in thetubes, the allowable turbine back pressure is lower with the delta 160design.

Furthermore, the above-described bundle design also reduces the pressuredrop within the individual delta 160. For example, the heat exchangethat takes place via the deltas 160, is dependent upon the heat exchangecoefficient, i.e., the mean temperature difference between air and steamand the exchange surface. Due to the reduced pressure drop as previouslydescribed, the mean pressure (average between inlet pressure and exitpressure) in the exchanger is higher with the design of the currentcondenser configuration 12. In other words, because steam is saturated,the mean steam temperature is also higher for the same heat exchangesurface resulting in increased heat exchange.

Turning now to FIG. 21, a transport container, generally designated 210is illustrated. As the name suggests, the transport container 210 isused to transport the bundles 30, from the factory to the job site. Asillustrated, the condenser bundles 30, are manufactured and assembled atthe factory with the respective steam manifold 204 and steam condensateheaders 200. While five (5) bundles are illustrated positioned in thetransport container, more or less individual bundles may be shipped percontainer depending as needed or required.

Alternatively, the above described embodiments of the present employtube bundles manufactured and assembled, prior to shipping, having steammanifold 204 and steam condensate headers 200, alternative embodimentbundles may not include a manifold prior to shipping. More specifically,in such embodiments, the tube bundles may be ship without steammanifolds 28 attached thereto. In said embodiments, the tube bundles 30may be assembled in field to form the A-type configuration, as discussedabove. However, instead of employing two steam manifolds, thisalternative embodiment may employ a single steam manifold wherein thesingle steam manifold extends along the “apex” of the A configuration.

Referring now to FIG. 22, a flow chart is illustrated, schematicallydepicting the steps of assembly of the air cooled condenser tower 12. Aspreviously described, the individual tube bundles 30 are assembled priorto shipment to the job site, as referenced by numeral 212. Eachindividual bundle assembly 30 includes a plurality of finned tubes 206along with a steam manifold 204 and steam condensate header 200. Aspreviously discussed in connection with the previous figures of thespecification, the bundle assemblies 30 are pre-manufactured at thefactory prior to placing the individual bundle assemblies 30 in theshipping container 210 as identified by numeral 42. The shippingcontainers 210 are then shipped to the erection field site.

Next, the delta, generally indicated as 160, is assembled in the fieldas identified by numerals 216 and 218. As previously described, whilethe bundles may be positioned at any desired angle, they preferably arepositioned at an angle (y) approximately twenty degrees (20°) toapproximately thirty degrees (30°) from vertical and an angle (x)approximately sixty degrees) (60° to approximately seventy degrees (70°)from horizontal. More specifically, the bundles are positioned attwenty-six degrees (26°) from vertical and sixty-four degrees (64°) fromhorizontal. As designated by numeral 220, a single A-type delta isillustrated 160 formed by two bundle assemblies 30 to form the “A”configuration. The bundle assemblies 30 self support one another in thisconfiguration.

Turning now to the air cooled condenser module 12 as referenced by thenumeral 220, it is depicted employing five deltas 160. As discussedabove, the air cooled condenser is an improvement over current aircooled condenser types and it has a high “pre-fabrication” level whichequates to reduced installation cost and reduced installation time.Moreover, the above-described design reduces the pressure drop, therebyproviding a more efficient heat exchange apparatus.

Tables 1 and 2 below show the number of parts utilized for a 32 moduleMulti-Delta and a 30 module A-Frame ACC designed for the same duty.There is a very dramatic decrease in pieces which translates in tosubstantially less construction labor and construction time.

TABLE 1 Multidelta Type 1 Number 2 Understrucure Columns 12 Bracing 36Horizontal beams 8 Other 26 Plenum Middle truss 1 Transversal truss 4Longitudinal truss 2 Octogonal structure 16 Fan deck plate 24 Bridge 4Horizontal wind bracing 4 Wind wall Horizontal girder 2 longitudinalWind wall Horizontal girder 0 transversal Sum of elements 278 Type 2Number 2 Understrucure Columns 12 Bracing 36 Horizontal beams 8 Other 26Plenum Middle truss 1 Transversal truss 4 Longitudinal truss 1 Octogonalstructure 16 Fan deck plate 24 Bridge 4 Horizontal wind bracing 4 Windwall Horizontal girder 0 longitudinal Wind wall Horizontal girder 0transversal Sum of elements 272 Type 3 Number 2 Understrucure Columns 6Bracing 6 Horizontal beams 6 Other 13 Plenum Middle truss 1 Transversaltruss 2 Longitudinal truss 2 Octogonal structure 16 Fan deck plate 24Bridge 4 Horizontal wind bracing 2 Wind wall Horizontal girder 2longitudinal Wind wall Horizontal girder 0 transversal Sum of elements168 Type 4 Number 2 Understrucure Columns 6 Bracing 6 Horizontal 6 beamsOther 13 Plenum Middle truss 1 Transversal truss 2 Longitudinal 0.5truss Octogonal 16 structure Fan deck plate 24 Bridge 4 Horizontal wind2 bracing Wind wall Horizontal girder 0 longitudinal Wind wallHorizontal girder 0 transversal Sum of elements 161 Type 5 Number 4Understrucure Columns 6 Bracing 6 Horizontal 6 beams Other 13 PlenumMiddle truss 1 Transversal truss 2 Longitudinal 2 truss Octogonal 16structure Fan deck plate 24 Bridge 4 Horizontal wind 2 bracing Wind wallHorizontal girder 2 longitudinal Wind wall sheeting support 1.5transversal Sum of elements 342 Type 6 Number 4 Understrucure Columns 6Bracing 6 Horizontal 6 beams Other 13 Plenum Middle truss 1 Transversaltruss 2 Longitudinal 0.5 truss Octogonal 16 structure Fan deck plate 24Bridge 4 Horizontal wind 2 bracing Wind wall Horizontal girder 0longitudinal Wind wall Horizontal girder 1.5 transversal Sum of elements328 Bundle bottom 256 girder External transversal walkways (withgrating) 320 Total assembly part for 32 modules multidelta 2125

TABLE 2 ACC Type 1 Number 1 Understrucure Columns 8 Bracing 24Horizontal beams 4 Support longitudinal 0 wind wall Fan deck Main beams4 Octogonal structure 16 Bridge Main truss 1 Bridge foot 4 Handrails 4Gratings 10 A-frame Columns 6 Top A 3 Bracings 8 Top girder 2 Minia-frame 4 Stick to middle of bridge 4 Hoist beam and support 4 Mida-frame tranversal 3 Mid a-frame 4 longitudinal Stick to end of bridge 4Internal girder and door 16 frame Angle for middle valley 4 sheetingWind wall Columns 0 longitudinal Horizontal girder 0 Bracings 0 Link toSDM 0 Tranversal walkway 0 Diamond plate 0 Wind wall Columns 0transversal Girders 0 Cleaning system Bottom rail 4 Top rail 4 Grating10 Sum of elements 155 Type 2 Number 2 Understrucure Columns 4 Bracing10 Horizontal beams 3 Support longitudinal 0 wind wall Fan deck Mainbeams 3 Octogonal structure 16 Bridge Main truss 1 Bridge foot 4Handrails 4 Gratings 10 A-frame Columns 4 Top A 2 Bracings 0 Top girder2 Mini a-frame 2 Stick to middle of bridge 4 Hoist beam and support 4Mid a-frame tranversal 2 Mid a-frame 4 longitudinal Stick to end ofbridge 2 Internal girder and door 8 frame Angle for middle valley 4sheeting Wind wall Columns 0 longitudinal Horizontal girder 0 Bracings 0Link to SDM 0 Longitudinal walkway 0 Diamond plate 0 Wind wall Columns 0transversal Girders 0 Cleaning system Bottom rail 4 Top rail 4 Grating 6Sum of elements 214 Type 3 Number 2 Understrucure Columns 4 Bracing 10Horizontal beams 3 Support longitudinal 0 wind wall Fan deck Main beams3 Octogonal structure 16 Bridge Main truss 1 Bridge foot 4 Handrails 4Gratings 10 A-frame Columns 4 Top A 2 Bracings 0 Top girder 2 Minia-frame 2 Stick to middle of bridge 4 Hoist beam and support 4 Mida-frame tranversal 2 Mid a-frame 4 longitudinal Stick to end of bridge 2Internal girder and door 3 frame Angle for middle valley 4 sheeting Windwall Columns 0 longitudinal Horizontal girder 0 Bracings 0 Link to SDM 0Longitudinal walkway 0 Diamond plate 0 Wind wall Columns 4 transversalGirders 20 Cleaning system Bottom rail 4 Top rail 4 Grating 6 Sum ofelements 252 Type 4 Number 2 Understrucure Columns 4 Bracing 10Horizontal 3 beams Support 4 longitudinal wind wall Fan deck Main beams3 Octogonal 16 structure Bridge Main truss 1 Bridge foot 4 Handrails 4Gratings 10 A-frame Columns 6 Top A 3 Bracings 8 Top girder 2 Minia-frame 4 Stick to middle 4 of bridge Hoist beam and 4 support Mida-frame 3 tranversal Mid a-frame 4 longitudinal Stick to end of 4 bridgeInternal girder 16 and door frame Angle for middle 4 valley sheetingWind wall Columns 7 longitudinal Horizontal girder 30 Bracings 6 Link toSDM 7 Tranversal 1 walkway Diamond plate 10 Wind wall Columns 0transversal Girders 0 Cleaning system Bottom rail 4 Top rail 4 Grating 0Sum of elements 380 Type 5 Number 4 Understrucure Columns 2 Bracing 4Horizontal 2 beams Support 2 longitudinal wind wall Fan deck Main beams2 Octogonal 16 structure Bridge Main truss 1 Bridge foot 4 Handrails 4Gratings 10 A-frame Columns 4 Top A 2 Bracings 0 Top girder 2 Minia-frame 2 Stick to middle 4 of bridge Hoist beam and 4 support Mida-frame 2 tranversal Mid a-frame 4 longitudinal Stick to end of 2 bridgeInternal girder 8 and door frame Angle for middle 4 valley sheeting Windwall Columns 6 longitudinal Horizontal girder 30 Bracings 6 Link to SDM6 Longitudinal 1 walkway Diamond plate 10 Wind wall Columns 0transversal Girders 0 Cleaning system Bottom rail 4 Top rail 4 Grating 0Sum of elements 608 Type 6 Number 4 Understrucure Columns 2 Bracing 4Horizontal 2 beams Support 2 longitudinal wind wall Fan deck Main beams2 Octogonal 16 structure Bridge Main truss 1 Bridge foot 4 Handrails 4Gratings 10 A-frame Columns 4 Top A 2 Bracings 0 Top girder 2 Minia-frame 2 Stick to middle 4 of bridge Hoist beam and 4 support Mida-frame 2 tranversal Mid a-frame 4 longitudinal Stick to end of 2 bridgeInternal girder 3 and door frame Angle for middle 4 valley sheeting Windwall Columns 6 longitudinal Horizontal girder 30 Bracings 14 Link to SDM5 Longitudinal 1 walkway Diamond plate 10 Wind wall Columns 3transversal Girders 17.5 Cleaning system Bottom rail 4 Top rail 4Grating 0 Sum of elements 698 Top Platform 21 Cleaning ladder 6 Externaltransversal walkways (with grating) 240 Total assembly part for 30modules ACC (2 units of 15 modules) 5148

As shown in Tables 1 and 2, the multidelta ACC of an embodimentdisclosed herein includes less than half the parts of a comparableconventional A-Frame ACC (2125 parts verses 5148 parts). This reductionin part numbers has a corresponding reduction in labor costs,construction time, and the like.

The many features and advantages of the invention are apparent from thedetailed specification, and, thus, it is intended by the appended claimsto cover all such features and advantages of the invention which fallwithin the true spirit and scope of the invention. Further, sincenumerous modifications and variations will readily occur to thoseskilled in the art, it is not desired to limit the invention to theexact construction and operation illustrated and described, for examplea forced draft air cooled condenser has been illustrated but an induceddraft design can be adapted to gain the same benefits and, accordingly,all suitable modifications and equivalents may be resorted to that fallwithin the scope of the invention.

What is claimed is:
 1. A method for assembling an understructure for amodular air cooled condenser extending along a vertical axis away fromhorizontal, comprising the method steps of: preparing a foundation for abraced bay; placing the braced bay on the foundation; assembling apre-constructed middle truss with a pre-constructed duct and risers;placing the assembled middle truss and duct on the braced bay; affixinga plurality of pre-constructed transversal structures to the braced bay;affixing a plurality of pre-constructed transversal trusses to theaffixed transversal structures; affixing a plurality of pre-constructedlongitudinal trusses to ends of the affixed transversal trusses; andaffixing a plurality of pre-constructed bridges between ones of theaffixed transversal trusses.
 2. The method according to claim 1, furthercomprising the method step of: affixing a header to each respectiveriser.
 3. The method according to claim 2, further comprising the methodstep of: affixing a top manifold to each respective header.
 4. Themethod according to claim 3, further comprising the method step of:affixing four of the top manifolds to each respective header.
 5. Themethod according to claim 4, further comprising the method step of:affixing a bundle to each respective top manifold.
 6. The methodaccording to claim 1, further comprising the method step of: fluidlyconnecting a return line to each bundle.
 7. The method according toclaim 6, further comprising the method step of: fluidly connecting thereturn line to a power plant.
 8. The method according to claim 1,further comprising the method step of: fluidly connecting a main steamline to the duct.
 9. The method according to claim 8, further comprisingthe method step of: fluidly connecting the main steam line to a powerplant.
 10. The method according to claim 1, further comprising themethod step of: affixing a bell housing and a fan to the understructure.11. A modular understructure for an air cooled condenser extending alonga vertical axis away from horizontal, comprising: a braced bay disposedon a foundation; an assembled pre-constructed middle truss with apre-constructed duct and risers disposed on the braced bay; a pluralityof pre-constructed transversal structures affixed to the braced bay; aplurality of pre-constructed transversal trusses affixed to the affixedtransversal structures; a plurality of pre-constructed longitudinaltrusses affixed to ends of the transversal trusses; and a plurality ofpre-constructed bridges affixed between ones of the transversal trusses.12. The modular understructure according to claim 11, furthercomprising: a header affixed to each respective riser.
 3. The modularunderstructure according to claim 12, further comprising the method stepof: a top manifold affixed to each respective header.
 14. The modularunderstructure according to claim 13, further comprising the method stepof: four of the top manifolds affixed to each respective header.
 15. Themodular understructure according to claim 14, further comprising themethod step of: a bundle affixed to each respective top manifold. 16.The modular understructure according to claim 11, further comprising themethod step of: a return line fluidly connected to each bundle.
 17. Themodular understructure according to claim 16, further comprising themethod step of: the return line fluidly connected to a power plant. 18.The modular understructure according to claim 11, further comprising themethod step of: a main steam line fluidly connected to the duct.
 19. Themodular understructure according to claim 18, further comprising themethod step of: the main steam line fluidly connected to a power plant.20. The modular understructure according to claim 11, further comprisingthe method step of: a bell housing and a fan affixed to theunderstructure.